package collection;

import java.util.ArrayList;
import java.util.List;

/**
 * List获取子集操作:
 *  List<T> subList(int start,int end):含头不含尾
 */
public class ListDemo3 {
    public static void main(String[] args) {
        List<Integer> list = new ArrayList<>();
        for(int i = 0; i < 10; i++) {
            list.add(i * 10);
        }
        System.out.println("list:" + list); //[0, 10, 20, 30, 40, 50, 60, 70, 80, 90]

        List<Integer> sublist = list.subList(3, 8); //获取下标3到7的子集
        System.out.println("sublist:" + sublist); //[30, 40, 50, 60, 70]

        //将子集每个元素扩大10倍
        for(int i = 0; i < sublist.size(); i++) {
            sublist.set(i, sublist.get(i) * 10);
        }
        System.out.println("subList:" + sublist); //[300, 400, 500, 600, 700]
        //注意:对子集的操作就是对原集合对应元素的操作
        System.out.println("list:" + list); //[0, 10, 20, 300, 400, 500, 600, 700, 80, 90]

        list.set(3, 1000); //将原集合对应下标3的元素修改为1000
        System.out.println("list:" + list); //[0, 10, 20, 1000, 400, 500, 600, 700, 80, 90]
        //原集合数据改变后, 子集数据跟着变了
        System.out.println("sublist:" + sublist); //[1000, 400, 500, 600, 700]

        list.remove(0);
        System.out.println("list:" + list); //[10, 20, 1000, 400, 500, 600, 700, 80, 90]
        //原集合长度改变后, 子集将不能再进行任何操作了, 若操作则发生异常, 但是可以重新获取子集
        //System.out.println("subList:" + sublist);
    }
}
